Before I explain what and how explicit tracking of group membership works in IGMP, let me give you a brief introduction to IGMP. A brief introduction to IGMP: Internet Group Management Protocol ( IGMP ) is used by end hosts and routers to exchange multicast group membership information. IGMP …
Read More »PIM Assert mechanism : Why and how
Protocol Independent Multicast (PIM) – Sparse mode (PIM-SM) is a multicast routing protocol. PIM-SM is used when receivers are sparsely populated. PIM-SM uses explicit-join mechanism. PIM-SM can work on point-to-point link and ethernet LANs. Why PIM Assert mechanism is required: We will use the network configuration shown in figure-1 …
Read More »What is Software Defined Networking (SDN) – Part 2
In my previous post, I explained what is Software Defined Networking (SDN). As I wanted to keep the introduction simple, I avoided discussing SDN internals in that post. Now that you understand what SDN is, let us get into other details. SDN Internals In SDN, sequence of packets exchanged between …
Read More »What is Software Defined Networking (SDN) – Part 1
The whole data communication industry is bullish about Software Defined Networking (SDN). What is SDN? Is it really a game changer? I think nobody knows that for sure because it is still evolving. While there have been some companies which have deployed SDN in their Data Centers, it is still not …
Read More »PING : The Most Used Networking Tool
Have you heard someone using a phrase ‘Can you ping me at 8:00 PM’ or ‘Please ping me when you are free’? I am sure you must have heard people using such phrases in their daily talks. I think its fairly obvious that they want the other person to check …
Read More »Any Source Multicast and Source Specific Multicast
Applications/Servers use IP multicast to send their contents in IP packets to a group of interested clients. These clients indicate their wish to receive such traffic explicitly by sending an IGMP (Internet Group Management Protocol) join message. In early years of IP multicast deployment, receivers and senders did not know …
Read More »IP TTL Security : Why and How?
TTL (Time-To-Live) is a field in the IPv4 header. TTL field is of 8 bits and so it can take a maximum value of 255. When a sender sends out a packet, it sets the TTL value (usually as 64) in the IP header. Each router that receives this packet, …
Read More »